Flow adjusting device for a pump turbine



1968 SHUNICHI FUKASU ETAL v 3,361,070

FLOW ADJUSTING DEVICE FOR A PUMP TURBINE Filed on. 29, 1965 INVENTORS SHuM/c/l/ Fakfisa Sumo omnnon ATTORNEY United States Patent Ofiice 3,3513% Patented Jan. 2, 1968 3,361,070 FLOW ADJUSTING DEVlCE FOR A PUMP TURBINE Shunichi Fukasu, Hitachi-sill, and Sojiro Oyamada, Sapporo-shi, Japan, assignors to Hitachi, Ltd, Tokyo, Japan, a corporation of Japan Filed Oct. 29, 1965, Ser. No. 5ll5,65 Claims priority, application .lapan, Dec. 24, 1%4, 39/72,521 3 Claims. (Cl. 103-97) ABSTRACT OF THE DISCLQSURE The present disclosure relates to a reversible water pump-turbine having a relatively large needle valve between its penstock and rotatable blades, with the needle valve being actuated by a double acting fluid pistoncylinder. A line is provided to bypass the needle valve and has therein a secondary or bypass valve.

It has been known that movable guide vanes have been conventionally mostly employed as a means for adjusting flow in water turbines or pumps which serve as Water turbines too. In such cases movable guide vanes have been disposed on the same circumference as the runner and adjacent the same. It is also well known that the movable guide vanes are eflective as a means for cutting olf water flow though they are chiefly intended for means to adjust water flow.

Another means for cutting ofl water flow is also well known, that is to say a gate valve connected to a penstock.

When a pump turbine is operated as a water turbine, the above mentioned movable guide vanes serve to adjust flow in accordance with the detected frequency fluctuation of the power transmission system so that the output of the water turbine generator may be adjusted properly, while when it is operated a a pump for raising water, discharge is adjusted by means of the movable guide vanes or the gate valve.

The conventional pump turbine as stated above, however, requires a group of movable guide vanes as a means for adjusting flow, which makes the construction much complicated. In addition, in pumping operation the movable guide vanes or other means for cutting off water flow, for instance butter-fly valves, are easily caused to have vibration. This takes place especially in cases of high lifts.

According to the present invention to avoid the disadvantages described above, a main valve means, for instance a large-sized needle valve means is employed in a pump turbine for adjusting output in Water turbine operation and discharge in pumping operation. The device of the present invention can not only relieve effectively difliculties with high head drops and high lifts but also simplifies the construction of the pump turbine.

Further, employment of a large needle valve means which is offered comparatively small fluid resistance as a main valve means reduces or prevents at all the vibrations.

The figure illustrates a sectional view of the invention.

There are other objects and particularities of the invention which will be explained in detail with reference to the accompanying drawing which is a horizontal sectional view roughly showing a flow adjusting device embodying the present invention. Reference numeral 1 indicates a runner in a pump turbine, and 2 is a casing. The valve body 3 of a needle valve means is disposed between a pressure steel pipe 4 and the casing 2. A needle valve 5 which is connected to a valve rod 6 is driven by a servo-motor 7.

When a working fluid is supplied into an upper chamber defined between the upper wall of the servo cylinder and a piston 11 mounted at the upper end of said rod 6 through a pipe 9 connected to said upper chamber, the piston 11 is moved downwardly to close the valve. When the working fluid is supplied into a lower chamber defined between the lower wall of the servo cylinder and the piston 11 through a pipe 8 connected to said lower chamber, the piston 11 is moved upwardly to open the valve. The servo-motor 7 works in accordance with instructions from such a means as a governor (not shown) which determines output of the water turbine generator or discharge of the pump in accordance with the purpose of operation i.e. water turbine operation or pumping operation. A bypass valve indicated by numeral 14 is operated in water turbine operation, or more precisely in the starting period and parallel operation of the water turbine.

In water turbine operation, the servo-motor 7 operates to drive the needle-valve 5 in accordance with the frequency fluctuation and predetermined programming of the power transmission system so that flow from the pressure steel pipe 4- into the casing 2 may be adjusted. (The predetermined programming above means the programming of power supply as set considering peak etc.)

On the other hand in pumping operation the needle valve 5 works to adjust discharge to be introduced into the upper water reservoir through the casing 22, the valve body 3 and the pressure steel pipe 4.

What is claimed is:

1. A reversible water pump-turbine, comprising: blade means operable as a reversible pump and turbine, having a casing; a penstock; main valve means mounted between said penstock and said casing for adjusting fluid flow; a bypass line directly connecting said penstock with said casing to bypass said main valve means; secondary valve means in said bypass line being operative to balance water pressure between said penstock and said casing when said reversible pump-turbine blade means is started and to eifect minute fluid flow control until said pump-turbine blade means is brought to synchronized operation.

2. A reversible pump turbine as claimed in claim 1, wherein said main valve means is a relatively large needle valve means for controlling the output or the quantity of water pumped and said secondary valve means is a bypass valve means for controlling the speed of said blade means.

3. A reversible pump turbine as claimed in claim 2, wherein said needle valve means includes a double acting fluid piston-cylinder actuator.

References Cited UNITED STATES PATENTS 1,220,403 3/1917 Doble 103-97 2,949,540 8/1960 Clayton 253-31 FOREIGN PATENTS 1,095,672 12/1960 Germany.

518,017 3/1955 Italy.

HENRY F. RADUAZO, Primary Examiner. 

